Existing traditional closed postage printing systems are secure printing systems that are restricted to printing postage and postage related items such as meter register reports. These systems must ensure that the secure printer cannot be used to produce fraudulent copies of postal indicia without leaving evidence of tampering. As a result, traditional closed postage printing systems are single purpose devices used to print postage and postage related reports. These systems in certain implementations are enclosed in a single secure tamper resistant housing.
This restriction on printing limits the usefulness of such postage printing systems. As a result, users often employ two printers, one for printing postage indicia and related items and another as a generic printer for printing other non-postal items. For example, a postage printing system that prints on labels may be able to print postage, return addresses and destination addresses. However, the printer could not be used as a generic printer to print other images such as a corporate logo in the return address or product labels since the images could be made to be copies of valid postage indicia.
Closed postage printing systems, where the printer is dedicated to printing postal indicia and other postal related items, may be a single unit or may be implemented as a peripheral device. If the printer is implemented as a peripheral device portions of the host application and printer controller may be implemented in a host computer such as a personal computer (PC). Similarly the host application may further be implemented as a combination of a host computer application and a data center application. The host application formats data to send to the printer controller for printing. The printer controller authenticates the data that is sent by the host application. The authentication can take many forms. The print controller may simply check to see that a communications protocol has been implemented correctly or may perform cryptographic operations to ensure the source and/or integrity and/or freshness of the data. After authenticating the data, the print controller converts the data into control signals that instruct the print engine how to print the document. The print engine includes motors and a mechanism to create an image on the document employing, for example, an ink jet or a thermal print head. The print engine may also communicate status to the printer controller including out of paper, out of ink, over temperature condition, and the like.